One of Marvel Studios' biggest missteps is arguably misusing Idris Elba's Heimdall. The character made numerous appearances in the MCU, but it wasn't really until Thor: Ragnarok that we got to see him step up to the plate (only for him to die just a few short minutes into Avengers: Infinity War).
Thor: Love and Thunder goes some way towards making up for past mistakes by introducing Heimdall's son, Astrid/Axl. Played by actor Kieron L. Dyer (Jingle Jangle: A Christmas Journey), he has the same powers as his father, but has yet to harness them. However, the youngster is able to use his Asgardian abilities to communicate with Thor when New Asgard's children are kidnapped by Gorr the God Butcher.
At the end of the movie, Axl is shown being trained by Sif (Heimdall's sister in the comic books) and it's briefly mentioned that he's now mastered his abilities.
How he will be used in the MCU in the future remains to be seen, though we can't help but think he'll be a key player in New Asgard moving forward. He doesn't have a comic book counterpart, so there are no clues there, but the character is one who could be aged up so that we essentially have a new Heimdall (a very intriguing prospect).
Alternatively, there's a chance he'll become a Young Avenger. His mother, Heimdall's widow, is called Grace and played by Eliza Matengu (Jack Irish). In a post-credits scene, Heimdall welcomes Jane Foster to Valhalla and thanks her for saving his son. Clearly, he's keeping his eye(s) on Midgard!
While we're on the subject of spoilers, Gorr's daughter, "Love," isn't from the comics and is another young character with an intriguing future. She's been imbued with God-like powers by Eternity, and based on Marvel Studios' track record, we'd be shocked if she doesn't grow up to become someone from the source material, similar to Layla El-Faouly being a combination of characters in Moon Knight.
Marvel Studios still hasn't made its Phase 4/5 plans clear, so we have no clue where any of these stories are heading. Something we can say for sure, however, is that these two characters will be worth keeping an eye on.